User Interfaces

This example shows how to use the UI API. We will demonstrate how to create several DIPY UI elements, then use a list box to toggle which element is shown.

First, a bunch of imports.

from fury.data import read_viz_icons, fetch_viz_icons

from fury import ui, window

Shapes

Let’s start by drawing some simple shapes. First, a rectangle.

rect = ui.Rectangle2D(size=(200, 200), position=(400, 300), color=(1, 0, 1))

Then we can draw a solid circle, or disk.

disk = ui.Disk2D(outer_radius=50, center=(500, 500), color=(1, 1, 0))

Add an inner radius to make a ring.

ring = ui.Disk2D(outer_radius=50, inner_radius=45, center=(500, 300),
                 color=(0, 1, 1))

Image

Now let’s display an image. First we need to fetch some icons that are included in DIPY.

fetch_viz_icons()

Out:

Data size is approximately 12KB
Dataset is already in place. If you want to fetch it again please first remove the folder /Users/koudoro/.fury/icons

Now we can create an image container.

img = ui.ImageContainer2D(img_path=read_viz_icons(fname='home3.png'),
                          position=(450, 350))

Panel with buttons and text

Let’s create some buttons and text and put them in a panel. First we’ll make the panel.

panel = ui.Panel2D(size=(300, 150), color=(1, 1, 1), align="right")
panel.center = (500, 400)

Then we’ll make two text labels and place them on the panel. Note that we specifiy the position with integer numbers of pixels.

text = ui.TextBlock2D(text='Click me')
text2 = ui.TextBlock2D(text='Me too')
panel.add_element(text, (50, 100))
panel.add_element(text2, (180, 100))

Then we’ll create two buttons and add them to the panel.

Note that here we specify the positions with floats. In this case, these are percentages of the panel size.

button_example = ui.Button2D(
    icon_fnames=[('square', read_viz_icons(fname='stop2.png'))])

icon_files = []
icon_files.append(('down', read_viz_icons(fname='circle-down.png')))
icon_files.append(('left', read_viz_icons(fname='circle-left.png')))
icon_files.append(('up', read_viz_icons(fname='circle-up.png')))
icon_files.append(('right', read_viz_icons(fname='circle-right.png')))

second_button_example = ui.Button2D(icon_fnames=icon_files)

panel.add_element(button_example, (0.25, 0.33))
panel.add_element(second_button_example, (0.66, 0.33))

We can add a callback to each button to perform some action.

def change_text_callback(i_ren, _obj, _button):
    text.message = 'Clicked!'
    i_ren.force_render()


def change_icon_callback(i_ren, _obj, _button):
    _button.next_icon()
    i_ren.force_render()


button_example.on_left_mouse_button_clicked = change_text_callback
second_button_example.on_left_mouse_button_pressed = change_icon_callback

Cube and sliders

Let’s add a cube to the scene and control it with sliders.

def cube_maker(color=(1, 1, 1), size=(0.2, 0.2, 0.2), center=(0, 0, 0)):
    cube = window.vtk.vtkCubeSource()
    cube.SetXLength(size[0])
    cube.SetYLength(size[1])
    cube.SetZLength(size[2])
    if center is not None:
        cube.SetCenter(*center)
    cube_mapper = window.vtk.vtkPolyDataMapper()
    cube_mapper.SetInputConnection(cube.GetOutputPort())
    cube_actor = window.vtk.vtkActor()
    cube_actor.SetMapper(cube_mapper)
    if color is not None:
        cube_actor.GetProperty().SetColor(color)
    return cube_actor


cube = cube_maker(color=(0, 0, 1), size=(20, 20, 20), center=(15, 5, 0))

Now we’ll add three sliders: one circular and two linear.

ring_slider = ui.RingSlider2D(center=(740, 400), initial_value=0,
                              text_template="{angle:5.1f}°")

line_slider_x = ui.LineSlider2D(center=(500, 250), initial_value=0,
                                min_value=-10, max_value=10,
                                orientation="horizontal")

line_slider_y = ui.LineSlider2D(center=(650, 350), initial_value=0,
                                min_value=-10, max_value=10,
                                orientation="vertical")

We can use a callback to rotate the cube with the ring slider.

def rotate_cube(slider):
    angle = slider.value
    previous_angle = slider.previous_value
    rotation_angle = angle - previous_angle
    cube.RotateX(rotation_angle)


ring_slider.on_change = rotate_cube

Similarly, we can translate the cube with line sliders. We use global variables to keep track of the position of the cube.

cube_x = 0
cube_y = 0


def translate_cube_x(slider):
    global cube_x, cube_y
    cube_x = slider.value
    cube.SetPosition(cube_x, cube_y, 0)


def translate_cube_y(slider):
    global cube_x, cube_y
    cube_y = slider.value
    cube.SetPosition(cube_x, cube_y, 0)


line_slider_x.on_change = translate_cube_x
line_slider_y.on_change = translate_cube_y

Range Slider

Finally, we can add a range slider. This element is composed of two sliders. The first slider has two handles which let you set the range of the second.

range_slider_x = ui.RangeSlider(
    line_width=8, handle_side=25, range_slider_center=(450, 450),
    value_slider_center=(450, 350), length=150, min_value=0,
    max_value=10, font_size=18, range_precision=2, value_precision=4,
    shape="square")

range_slider_y = ui.RangeSlider(
    line_width=8, handle_side=25, range_slider_center=(750, 400),
    value_slider_center=(650, 400), length=150, min_value=0,
    max_value=10, font_size=18, range_precision=2, value_precision=4,
    orientation="vertical", shape="square")

Select menu

We just added many examples. If we showed them all at once, they would fill the screen. Let’s make a simple menu to choose which example is shown.

We’ll first make a list of the examples.

examples = [[rect], [disk, ring], [img], [panel],
            [ring_slider, line_slider_x, line_slider_y],
            [range_slider_x, range_slider_y]]

Now we’ll make a function to hide all the examples. Then we’ll call it so that none are shown initially.

def hide_all_examples():
    for example in examples:
        for element in example:
            element.set_visibility(False)
    cube.SetVisibility(False)


hide_all_examples()

To make the menu, we’ll first need to create a list of labels which correspond with the examples.

values = ['Rectangle', 'Disks', 'Image', "Button Panel",
          "Line & Ring Slider", "Range Slider"]

Now we can create the menu.

listbox = ui.ListBox2D(values=values, position=(10, 300), size=(300, 200),
                       multiselection=False)

Then we will use a callback to show the correct example when a label is clicked.

def display_element():
    hide_all_examples()
    example = examples[values.index(listbox.selected[0])]
    for element in example:
        element.set_visibility(True)
    if values.index(listbox.selected[0]) == 4:
        cube.SetVisibility(True)


listbox.on_change = display_element

Show Manager

Now that all the elements have been initialised, we add them to the show manager.

current_size = (800, 800)
show_manager = window.ShowManager(size=current_size, title="DIPY UI Example")

show_manager.scene.add(listbox)
for example in examples:
    for element in example:
        show_manager.scene.add(element)
show_manager.scene.add(cube)
show_manager.scene.reset_camera()
show_manager.scene.set_camera(position=(0, 0, 200))
show_manager.scene.reset_clipping_range()
show_manager.scene.azimuth(30)

# To interact with the UI, set interactive = True
interactive = False

if interactive:
    show_manager.start()

window.record(show_manager.scene, size=current_size, out_path="viz_ui.png")